Multiple HPV genotypes in cervical carcinomas: improved DNA detection and typing in archival tissues.

BACKGROUND Human papillomaviruses (HPV) have been considered to be the necessary and central agents of cervical carcinoma. OBJECTIVE The aim of this study was to determine the prevalence and genotypes of HPV in archival cervical carcinomas. STUDY DESIGN The study included 152 paraffin-embedded, formaldehyde-fixed cervical carcinoma specimens. To improve the detection and typing of HPV in archival tissues, we conducted a comprehensive study in which, polymerase chain reaction (PCR)-based methods using E7 type-specific (TS) and L1 modified general primers (MY11/GP6+ and GP5+/GP6+) were employed. RESULTS Overall HPV prevalence was 98% in the cervical carcinomas. HPV 16 was detected in 66% of the tumors, HPV 18 in 22%, HPV 31 in 13%, HPV 33 in 9%, and HPV 58 in 9%. Notably, multiple HPV types were present in 44 (28.9%) of the 152 cervical carcinomas. The most common co-infections were HPV types 16/18 (12 cases), followed by HPV types 16/31 (7 cases). Additionally, HPV 18 was more frequent in adenocarcinomas and adenosquamous carcinomas (86%) than in squamous cell carcinomas (15.8%) (P = 0.0002). CONCLUSIONS The combination of L1 general primers and E7 type-specific primers can be of use in detecting HPV DNA in archival tissues. The present study showed a high frequency of multiple HPV infections in cervical carcinomas. Hence, relevant HPV typing information in cervical carcinoma is very important for further HPV vaccine design and application.